Tim Cook says Steve Jobs' death was 'one of the saddest days' of his life

Apple chief Tim Cook admitted at the D10 conference on Tuesday that the loss of Steve Jobs last year was "one of the saddest days" of his life, while noting that he was taking Jobs' advice to move on and find "joy in the journey."

Cook took the stage Tuesday evening with journalists Walt Mossberg and Kara Swisher to kick off the tenth All Things D conference. During the interview, Mossberg asked the executive what he learned from Jobs and what he is doing different.

"It was absolutely one of the saddest days of my life when Steve passed away," Cook said with visible emotion.

With the world's most valuable company to run, Cook didn't have the luxury of a long grieving process. "At some point late last year, somebody kind of shook me and said, 'It's time to go on.'"

Cook did move on, channeling his sadness into a desire to carry on Jobs' legacy. One of the lessons he learned from Jobs was to focus both in products and in his personal life. He added that he had learned to do a few things great and cast everything else off.

The CEO went on to highlight Apple's unique culture of excellence and vowed not to "witness or permit the change of it."

Cook said he had learned from Jobs that "the joy is in the journey" and that "that life is fragile, tomorrow isn't guaranteed so give today your all."

Jobs himself left instructions with Cook and the rest of Apple's core team not to focus too much on asking themselves what he would do. According to Cook, Jobs cited Disney as an example of a company that suffered because it tried too hard to imagine what founder Walt Disney would have done even after he had passed away.

While Cook remains committed to preserving the culture at Apple, he also admitted to making changes at Apple, such as a matching gift program, which launched last September, and a new dividend and share buyback program announced in March. Cook did say that Jobs knew about the matching gift initiative and was supportive of it.

During the interview, Cook also took time to praise Jobs for having the "courage" to admit he was wrong, calling Jobs' ability to change his mind "an art."

"He would flip on something so fast that you would forget that he was the person that was taking the 180 polar position on it the day before," Cook said, eliciting chuckles from the audience.

Cook took over as Apple's CEO last August after Jobs' ailing health left him unable to meet the "duties and expectations" of the role. Since taking the helm, Cook has been carefully scrutinized by investors and pundits alike. A recent profile by Fortune's Adam Lashinsky described Apple under Cook as being "slightly more open and considerably more corporate."

Visit AppleInsider'sD10 archive for more of Cook's comments and ongoing coverage of the conference.